Baseball bats in the early days of baseball came in all shapes and sizes. In the 1850's, baseball was a very young sport and players often made their own bats. Because bats of all shapes and sizes were being used, a rule was made limiting bats to 2.5 inches in diameter, although they could be of any length. Ten years later another rule was added limiting bat length to 42 inches, the same maximum length allowed today. In 1890, another rule was added requiring bats to be round in shape and increasing the maximum diameter to 2.75 inches.
In 1924, U.S. Pat. No. 1,499,128 issued for a metal baseball bat. Aluminum bats began to be utilized in baseball play about 1970. Although aluminum bats do not provide the traditional “crack of the bat” sound of wooden bats, they have become far more popular than wooden bats in leagues that allow their use. One advantage of aluminum, or other types of metal, bats is that they are lighter and stronger than wood bats. Another advantage relates to the “spring effect” that occurs when a ball is hit with a metal bat. The spring effect occurs when the thin metal wall of the bat flexes upon contact with the ball, increasing the speed at which the ball leaves the bat.
However, when temperatures drop below about 60° F. metal bats incur numerous drawbacks. Colder temperatures reduce the elasticity of the bat material thus reducing their performance. In addition, metal bats tend to dent and/or crack when used in colder temperatures reducing their useful life. Because most metal bats utilize expensive metal alloys and require difficult manufacturing processes they are often expensive to purchase or replace.
Therefore, there have been attempts in the art to improve the performance and extend the useful life of metal bats when used in cold weather environments. For example, U.S. Pat. No. 5,786,574 discloses a cylindrical insulated sleeve that uses a battery to supply direct current to a heating wire to warm a baseball bat.
U.S. Pat. No. 6,247,469 discloses a warmer for a sporting element. The device includes a pouch constructed of an inner thermally conductive cloth layer and an outer cloth layer of thermally insulating material. An intermediate layer of a microwave heatable substance is placed between the inner and outer layers for heating a bat.
U.S. Pat. No. 6,229,132 discloses a sporting equipment warmer having a microwaveable heat source. The device includes a flexible cloth pouch sized and shaped to accept a bat. A microwaveable heat source is placed within the pouch cavity to transfer heat to the item placed inside.
U.S. Pat. No. 6,196,217 discloses a solar powered bat warmer. The device includes a container having four sides, a top and a bottom. One side is constructed of a plexiglass material and an opposite side includes a support to permit the container to be angled for collecting the sun's rays.
While these devices are suitable for warming bats in limited circumstances, they generally suffer from numerous drawbacks. The microwave heated elements are only capable of providing heat for a limited amount of time. Microwave ovens are generally not available in baseball or softball field dugouts. Therefore, if travel is required to get to the field or if there is a delay in the start time of the game these devices may cease to provide heat to the bat. The battery powered devices are only capable of providing a very limited amount of heat. In addition, the substantial drain on the batteries forces a user to change them often.
It is also known in the art to provide an enclosure into which the entire bat may be placed and heated. For example, U.S. Pat. No. 5,687,705 discloses an aluminum baseball or softball bat warmer. The device includes an inner and an outer container separated by an air space. The inner container is constructed to receive a bat and is supported inside of the outer container on a hanger. A convective heat source is positioned below the hanger. Warmed air from the convective heat source is directed through an aperture in the hanger to warm the inner container and the bat therein.
U.S. Pat. No. 6,222,159 discloses a warmer for baseball bats. The device consists of an enclosure with capped, suspended, open ended tubes for receiving multiple bats in a vertical position. The tubes are retained on a height-adjusting grate. A convective thermal heat source is positioned below the retaining grate. Warmed air from the heat source rises through the grate heating the bats in the capped cavities above.
While these devices are effective for heating bats, they suffer from numerous drawbacks that have not been addressed in the prior art. One such drawback relates to the method of transferring heat energy from the heat source to the bat. The prior art utilizes convection heat sources positioned below the bat(s) within the enclosure. This method of heating generally results in excessive temperatures at the distal ends of the bat. Heat transfer to the remainder of the bat relies on conduction through the bat material. Because convective heat rises, the grip portion of the bat is excessively heated. This portion of the bat is not constructed to withstand repeated exposure to heat. Repeated heat cycles cause a loss of plasticizers within the resilient grip portion causing it to become dry and/or brittle. This shortens the useful life of the bat by requiring the grip portion to be replaced at short intervals. Because the grip portion is often molded around the handle of the bat this may be impractical and require the bat to be replaced.
Therefore what is needed in the art is a modular bat heating system that is capable of selectively heating the barrel portion of the bat via a radiation heat source while isolating the handle and grip portion of the bat from excessive heat. The system should provide a modular design that allows for heating one bat or a plurality of bats. The system should provide portability and allow for fixed placement if desired.